Core mechanics

Unlike the other fighters, Pokémon Trainer doesn't actually fight his opponents himself. Instead, he sends out his Pokémon team of Squirtle, Ivysaur, and Charizard to fight on his behalf, each with its own set of moves, strengths, and weaknesses. The Trainer is able to switch between the three Pokémon using the Down-Special move, Pokémon Change, which each Pokémon has access to. If a Pokémon fights for too long, it will gradually weaken. The Pokémon Trainer's Final Smash, Triple Finish, is performed by all three Pokémon at once.

During a fight, the Pokémon Trainer can be seen in the background, using hand signals and commands to direct his Pokémon, and running across the screen (on large stages) so he can be near his Pokémon at all times. When his Pokémon are defeated, he remains in the background, but pulls his hat over his eyes and assumes a defeated posture.

Type effectiveness

A simplified form of type effectiveness is implemented for each of the three Pokémon: Squirtle is weak to Grass and resists Fire, Ivysaur is weak to Fire and resists Water, and Charizard is weak to Water and resists Grass. A resisted attack does 0.9x knockback, while a super-effective attack does 1.1x knockback. No characters aside from another Pokémon Trainer (or a Kirby having copied one) have access to damaging Grass- and Water-type attacks, but several characters have KO-capable Fire-type attacks, which overall gives Squirtle more survivability and cuts Ivysaur's noticeably. It also heavily affects matches where one Pokémon Trainer faces another, as each player will try to switch to gain the advantage.

Pokémon Change

The order in which Pokémon Change will rotate (Squirtle→Ivysaur→Charizard)

When sent out, each Pokémon is initially granted 100 points of energy called stamina. 0.5 points of stamina is deducted for every second a Pokémon is in battle, thus allowing for a maximum of approximately 3 minutes and 20 second of normal performance. Executing an attack also drains 0.5 stamina points. When a Pokémon's stamina reaches 40, their stance will change to signal oncoming fatigue. Once stamina reaches 0, the Pokémon's attacks drop in effectiveness to 0.7x damage. When any Pokémon is knocked out, the stamina of all three is increased by 30%.

Pokémon Change mimics anime/manga-style battling by switching out to the next available Pokémon to let the previously used one rest; while not in battle, each Pokémon will regenerate 0.8 points of stamina per second (until restored to 100).

While switching out, the user is temporarily immune to any on-screen attacks. This makes it an effective method for avoiding certain Final Smashes if timed correctly. Damage percentage is shared by all 3 Pokémon, so changing Pokémon will not affect damage at all. Effects such as increased or decreased size held by the previous Pokémon will not be carried over during Pokémon Change (Final Smash wielding being one exception). Pokémon Change cannot be activated in midair.

Due to the Pokémon Trainer starting with only Squirtle, Pokémon Change is disabled in The Subspace Emissary until the player obtains Ivysaur; it is then limited until Charizard is obtained.

Pokémon

Squirtle is a fast, lightweight fighter and uses various attacks using its shell and jets of water. It can use Waterfall to dash upward on a wave of water to recover from falls, Withdraw to retreat into its shell and propel itself forward while shooting water out; which makes up for its below-average dash speed. It also uses Water Gun to push enemies backward with a chargeable stream of water, but does no damage at all (unless fired without charging it up, though it also shortens the range). Because of its lightweight build, it excels in aerial combat and is hard to combo, but is easy to knock around and KO. Squirtle is also the shortest-ranged of the 3 Pokémon and needs to be in close range to deal damage, due to its small size and poor reach. It uses Hydro Pump in the Pokémon Trainer's Final Smash, Triple Finish.

In many ways, Ivysaur is the balance between the heavyweight, hard-hitting Charizard and the lightweight, agile Squirtle. Despite this, it lacks the heavy-hitting moves of Charizard and the fast attack rate of Squirtle. It is very good at racking up damage percentages with its attacks, but has a very hard time KOing its opponent since its strongest finishing moves are too slow to pose a threat. Ivysaur especially suffers in aerial combat and recovery. Despite these flaws, Ivysaur can be used to irritate its foes and rack up damage with its attacks (especially Bullet Seed). Its throws are decent, as its forward and down throws can leave the opponent vulnerable to combos. It uses mostly physicalGrass-type attacks, such as Bullet Seed, a rapidly upward-hitting move, and Vine Whip, a tether recovery move that shoots vines out to latch onto edges of a stage and pull Ivysaur up. Like all tether recoveries, however, Vine Whip can be edgehogged, sending Ivysaur to its doom. It also uses the projectile attack Razor Leaf. It uses Solar Beam in the Pokémon Trainer's Final Smash, Triple Finish.

In the Subspace Emissary, Ivysaur is found by the Pokémon Trainer, Squirtle, and Lucas after an encounter with Ness's captor, Wario; it is captured in trophy form in The Ruins. This allows the Pokémon Trainer to use Pokémon Change in the story mode.

Charizard is the Pokémon Trainer's powerhouse, boasting heavy-hitting moves, above-average dash speed (slightly faster than Pikachu), and long-range attacks. Charizard's drawbacks include large weight, subpar aerial game, and slow walking speed. Its varied arsenal of attacks includes Rock Smash, a powerful frontal attack, and Fly, a recovery move that sends Charizard skyward and allows it to glide. It can also use Flamethrower to attack from a short distance, but its power decreases over time. It uses Fire Blast in the Pokémon Trainer's Final Smash, Triple Finish.

In the Subspace Emissary, Charizard is found shortly after Ivysaur. After being defeated in battle, it is turned into a trophy and captured, completing the Trainer's team.

Subspace Emissary

The Pokémon Trainer is first encountered by Lucas in the Ruined Zoo. For most of the game, the two are paired together. Pokémon Trainer's mission is to capture Charizard and Ivysaur while Lucas's is to save Ness. On their way to the Ruins, the two are ambushed by Wario, who is eventually defeated by the two. Later in The Ruined Hall, they are attacked by Galleom. Once defeated, it sets off a time bomb. Lucas saves the Pokémon Trainer, and they are then both saved by Meta Knight who carries them away from the explosion, which sucks up Wario's trophy into Subspace. From then on, the two join Meta Knight, Marth, and Ike on their quest to take down the Subspace Army.

Solid Snake:"So he makes his Pokémon fight while he sits back and watches. Sounds like a good deal if you ask me."

Roy Campbell:"It's not like that, Snake. Those Pokémon wouldn't know what to do if the Pokémon Trainer wasn't there giving orders. In every battle, there's a soldier doing the fighting, and a commander telling him what to do. By working together as a team, they accomplish much more than either could on their own. So let's do this together, partner."

Solid Snake:"…Yeah… Whatever you say, Colonel."

Trophy information

Pokémon Trainer's Final Smash

Brawl

Pokémon Trainer

"A person who raises Pokémon and trains them as partners in battle. In battle, a Trainer gives orders to the Pokémon and uses items. It's not an exaggeration to say battles can be won or lost on a Trainer's single strategic move. Trainers pour their hearts into their Pokémon and share anger, sadness, and joy as they adventure in hopes of becoming Pokémon Masters."

Triple Finish

"The Final Smash of the Pokémon Trainer. Squirtle, Ivysaur, and Charizard join forces to simultaneously use Hydro Pump, SolarBeam, and Fire Blast. This is the only time all three of them appear on the screen together, so this move boasts the strength of three in one. A window will appear on the screen saying "It's super effective!" when the attack hits."

Charizard

"A Flame Pokémon. Its fiery breath is hot enough to burn up rocks, and its wings let it fly up to 4,600 feet into the air. It's a proud Pokémon that will never use its flame breath on an opponent weaker than itself. The flame on its tail is a barometer of how much vitality it has remaining. Its signature move, Flamethrower, is a reliable technique."

Squirtle

"A Tiny Turtle Pokémon. In times of danger, it pulls its arms and legs inside its shell to protect itself from enemy attacks. When it conceals its neck, it also shoots a powerful stream of water from its mouth. Its shell not only protects its body, it also reduces water friction when it's in the water. When it levels up, it evolves into Wartortle."

Ivysaur

"A Seed Pokémon that is the evolved form of Bulbasaur. It has a flower bulb on its back, the weight of which has made it develop strong legs and hips. If the blossom gets too big, the Pokémon can't stand on two legs alone. At a certain level, it evolves into Venusaur. When this happens, the bulb absorbs nutrients and blossoms into a large-petaled flower."

PAL: Quiz time! What do Misty, Brock, Cynthia, Iris and Ash all have in common? That's right - they're all Pokémon Trainers! This Pokémon Master in the making is just the same. He fought to be the very best - like no one ever was - back in Super Smash Bros. Brawl. To smash them was his real test - to launch them was his cause.

Trivia

If Ivysaur is grabbed, the opposing character grabs its bulb rather than its whole body, even when grabbing in front of it.

Squirtle is tied with Olimar as the smallest playable character in the game.

When the heroes reach the final boss of the Subspace Emissary, Tabuu, he unleashes his Off Waves, instantly turning them all into trophies. Because he does not fight opponents directly, this is the only time in the entire game when the Trainer himself is turned into a trophy.

There are unused animations of the Pokémon Trainer jumping and landing within the game code.